A hot-melt adhesive is a solvent-free adhesive and has a characteristic that instant bonding and high-speed bonding can be achieved since adhesiveness is exhibited after the adhesive is melted by heating and coated onto an adherend, followed by cooling to solidify the adhesive, and therefore has been used in a wide range of fields. Not only adherends to be bonded with such a hot-melt adhesive but also the conditions of use thereof are various. At present, various hot-melt adhesives for use in various applications have been developed and supplied to the market. Also for the conditions of use, various operating temperatures ranging from low temperatures to high temperatures are considered.
A propylenic polymer has heretofore been used as a base polymer for hot-melt adhesive. Above all, a low-molecular-weight polypropylene produced through polymerization using a metallocene-based catalyst has high flowability and is excellent in coatability when used as a hot-melt adhesive; and is excellent in adhesive strength with a low-polar substance such as polypropylene or the like and excellent in heat stability in melting under heat, it is favorably used as a base polymer for various kinds of hot-melt adhesives (PTL 1). In particular, it is suitable for spray coating for use in constructing hygienic materials such as paper diapers, sanitary goods, etc.